mercw124

The heater wires for my o2 sensor is getting no power. What could be the source of this problem? Thanks

Plutoe

At what disconnected connector did you make that observation???

mercw124

At the connector underneath the passenger side floor mat. Heater wires get no power and the sensor wires stays constant at about .45 volts. They were not disconnected when I tested it and the car was running and warmed up.

Plutoe

It would save me loads of search time if could provide the VIN!!

mercw124

0095429317
I'm pretty sure that's the part number. My car is a 1990 300E. Those connectors are located underneath the passenger side floor mat and that's where I tested the volts.

Plutoe

FYI the part number(not a VIN)you provided is not for you car--that part is for a 300SE or 300SEL---be careful in what you are doing

mercw124

Are you sure that's not the correct part? I'm pretty sure that's the same thing as the Bosch 13146 which is the oem part.
I am aware I gave a part number to you and not a VIN. Yes I know what a VIN is. It has both numbers and letters in it. From looking at the numbers you gave I assume you want the model and engine numbers though.
Those numbers are 124.030 and 103.983

Plutoe

Yes I am sure the part number you provided is not for the car you think you drive---that is why most folks who offer help will request a VIN repeat a VIN not a part number to confirm!!

Plutoe

The applicable part for your VIN is 009 542 91 17---there are no revisions

mercw124

Ok and back to the original question. Why could it be that the heater wires get no power?

Plutoe

After spending to much time on this, my belief is that the O2 heating voltage comes from the fuel pump relay---However after looking at the KE3 mixture info and your test(an open-no voltage) I simply believe that you have a faulty O2 sensor.

mercw124

Ok thank you for your time and help.